Initial Python 3 compatible code

src/sessionmanager/__init__.py

@@ -6,4 +6,5 @@ Contents of this package:
 	session_exceptions: Some useful exceptions when there is an error.
 	manager: Handles multiple sessions, setting the configuration files and check if the session is valid. Part of the model.
 	session: Creates a twitter session for an user. The other part of the model.
-"""
+"""
+from __future__ import unicode_literals